The runners completed two 1 mile timed runs on two separate days (72 hours apart) as well as a VO2max test. For the 1 mile timed run subjects completed an initial 5 minute treadmill warm-up and then either completed static stretches (6 different lower body stretches – 3 sets of 30seconds for each stretch) or sat still for ten minutes.

What the researchers found:

The researchers found that the time to complete the run was significantly quicker when subjects didn’t complete the pre-exercise stretches. The researchers also observed that the ground contact time and muscle activation increased following static stretching – both an increase in ground contact time and increased muscle activation indicate decreased efficiency. Interestingly another recent study looking at muscle strength after static stretching reported decreased lower body stability following static stretching.

The researchers concluded that static stretching negatively affects performance during short endurance bouts.

Practical applications

The researchers recommended that static stretching should be avoided before short bouts of endurance exercise. All though this research was limited to the effect of stretching on 1 mile run performance, previous research has demonstrated reduced muscle strength endurance, maximum strength, and exercise efficiency, and therefore should probably be avoided prior to competing in events where reduced stability may negatively affect exercise performance.

]]>Stretching before exercise impairs muscular performancehttp://www.strengthandfitnessuk.com/news/muscle-and-strength-training/stretching-before-exercise-impairs-muscular-performance
The benefits of pre-exercise stretching has been widely debated and researched over recent years, with most research failing to find any benefit. Despite this stretching is still actively encouraged by many fitness professionals as part of a pre-exercise warm-up routine. Recent studies have provided further evidence that stretching before exercise may not be of benefit and may actually be detrimental to exercise performance.

The first study was a meta-analytical review published in the Scanadian Journal of Medicine & Science in Sports (Simic et al., 2013). The researchers analysed 104 studies and found that static stretching negatively affected strength, power and explosive performance. The negative effect of static stretching was not related to fitness level, age or gender. The researchers concluded that static stretches should not be the primary activity of a workout and should be generally avoided.

The second study, published in the Journal of strength and conditioning research (Gergley JC, 2013), compared the effects of active dynamic warm-up with a combination of passive static stretches and the active dynamic workout. The researcher observed significant decreases in 1 repetition maximum barbell squat (~8%) and lower body stability (~22%) following static stretching. The researcher suggested that possible explanations for the negative effects of static stretching could be due to decreased joint stability or impaired neurologic function. It was suggested that intensive stretching should be avoided before lower body training. Instead the researcher suggested that an active dynamic warm-up may be more appropriate – in this study the active dynamic warm-up consisted of resistance exercises (leg extension, leg curl, and barbell squat).

Whilst the studies relate to muscle and strength training they should be applicable to other training areas such as endurance training, team sports, and general gym/fitness activities since muscle strength and power influence a number of performance factors. In fact previous research (Nelson et al., 2005) has shown that static stretching can significantly reduce muscle strength endurance (>25%). In particular static stretching may negatively affect endurance exercise performance by reducing exercise efficiency (Esposito et al., 2012).

Summary of stretching and muscular performance:

Whilst the exact mechanisms by which static stretching negatively affect muscular performance are not fully clear, most research does not support it’s use during the warm-up phase of exercise. The negative effects of stretching appear to affect a wide range of activities from resistance training through to endurance training and in all these activities an active dynamic warm-up appears to be more beneficial. In the case of resistance training this would involve the use of lighter weights or resistance machines to warm up the muscles to be used in the workout. In the case of endurance sports, team sports, or fitness activities light aerobic activities should be the primary focus of the warm-up but you may also wish to include body weight exercise (not to failure – ideally no more than 25-50% of the repetitions required to reach failure) such as partial squats, calf raises, press-ups etc.

My thoughts on pre-exercise stretching:

I stopped utilising pre-exercise stretching around 10 years ago mainly due to its possible implication in reduced exercise economy and haven’t noticed any negatives since. This is not to say that I don’t stretch, I just don’t use static stretching before exercise and tend to reserve it for times when I feel it necessary such as if I have a specific area that feels like it needs stretching or has a reduced range of motion. For me it was a case that my joints were quite mobile anyway and I felt less efficient after stretching and seemed to benefit from eliminating it from my pre-workout routine.

Decreasing your time spent stretching

If you have utilised pre-exercise stretching for a number of years and are worried about whether suddenly stopping pre-exercise stretching may increase your risk of injury you could gradually decrease the time spent stretching over a period of weeks e.g. if you normally complete 3 sets of 30 second stretches per muscle group, you could reduce this to 20 seconds for the first two weeks and then 15 seconds for the next two etc. In the meta-analysis study the researchers observed that the time spent stretching influenced the negative effects of static stretching and therefore any reduction in the time you spend stretching should have a positive effect so if you are reluctant to completely eliminate stretching you may find a benefit from simply reducing the overall time spent stretching.

]]>High intensity uphill interval training improves 5km running performancehttp://www.strengthandfitnessuk.com/news/endurance-training/high-intensity-uphill-interval-training-improves-5km-running-performance
Hill training is known to be a highly specific form of resistance training that can enhance endurance running performance. Recent research (Barnes et al., 2013) looked at the effect of different hill running interval training programs on 5km running performance in twenty well trained endurance runners. The runners initially underwent a series of tests including an incremental exercise test, jumps on a force plate and a 5km time trial. The runners were then randomly assigned to one of 5 uphill interval running workouts and following 6-weeks of training they underwent the same series of tests.

The effect of hill running programs on 5km time trial performance

Interestingly the researchers observed that there didn’t appear to be an optimum intensity for improving 5km time trial performance, with all hill training intensities leading to similar improvements in 5km time trial performance (~2%)*. However they observed greater improvements in running economy amongst the high intensity uphill interval training, and greater improvements in aerobic measures in the mid intensity groups. The researchers concluded that any form of high intensity uphill interval training will benefit 5km running performance.

*There was no information available regarding the exact intensities used for the high intensity uphill running.

Practical implications from the hill running research

Whilst there was no specific information available about the exact intensities used within this research we can assume that intensities used were in the range of ~90-100% VO2max since the researchers were using high intensity uphill running – high intensity interval training is normally used to describe intensities in the range of 90-100%VO2max. Since the researchers found different benefits to training in both the high range (improved economy) and mid range (improved aerobic measures) it seems logical to use different intensities within training to maximise the training benefit of uphill running i.e. hill session 1 = 10mile pace hill repeats, hill session 2 = 10k-5k pace hill repeats. Therefore look to mix up the intensities by utilising different hill interval sessions on a weekly basis. You can read about specific hill training sessions on the following pages: 1) Short hill intervals; 2) Long hill intervals; 3) Tempo hill intervals.

]]>Whey protein isolate improves recovery following endurance exercisehttp://www.strengthandfitnessuk.com/news/endurance-training/whey-protein-isolate-improves-recovery-following-endurance-exercise
One area of nutrition often overlooked by endurance athletes is the importance of adequate protein consumption for effective recovery between and after endurance training workouts. Recently researchers (Hill et al., 2013) looked at the effect of consuming either a high or normal amount of protein on markers of endurance training adaptations and recovery, following endurance exercise in a group of six healthy endurance trained cyclists and triathletes (age 29 ± 4 years, weight 74 ± 2 kg, VO2 max 63 ± 3 ml/kg/min, height 183 ± 5 cm;).

About the research:

The dietary intervention: The researchers divided the subjects into two groups and both underwent a 16-day dietary intervention in which they were provided with all their meals and snacks. The two dietary interventions contained the same total calories and amount of carbohydrate (8g per kg/bodyweight/day), the only differences were the proportions of protein and fat in the diet – the high protein diet group consumed twice the amount of protein (2.4g vs 1.2g per kg/bodyweight/day) whilst the normal protein intake group had increased fat intake to ensure they consumed the same total calories as the high protein group (1.7g vs 1.1g per kg/bodyweight/day). The extra 1.2g kg/bw/day protein was provided through a sports drink containing whey protein isolate. Following 14-days of dietary intervention both groups underwent a 2-day carbohydrate loading phase in which carbohydrate intake was increased to 10g per kg/bw/day (both groups) – the protein and fat intakes were maintained at the same level as the first 14-days of the dietary intervention.

The two dietary interventions:

The exercise tests: Prior to the dietary intervention subjects undertook a laboratory test, consisting of 3 sub-maximal workloads followed by an incremental test (25-watt increments every minute) to establish workloads for the post dietary intervention exercise trial. The exercise trial consisted of 60 minutes at 70% VO2max followed by 2mins rest and then exercise to failure at 90% of VO2max. Following the completion of the exercise trial subjects remained in the lab for a 6-hour recovery period. During the recovery period they consumed a recovery drink containing the same amount of carbohydrate (4g kg/bw) but different amounts of protein (1.1g vs 0.4g kg/bw in the high and normal protein groups respectively) and fat (0.4g vs 0.6g kg/bw in the high and normal protein groups respectively).

What the researchers found:

Muscle glycogen levels were not significantly different between the two groups either before during or after exercise. However, the rate of glycogen re-synthesis was enhanced after 6hours recovery in the whey protein isolate group but not the carbohydrate group.

There was increased plasma insulin levels during the recovery phase in the whey protein isolate group compared with the carbohydrate group.

The researchers observed significantly increased PGC-1α mRNA expression – an indicator of mitochondrial biogenesis which is an important adaptation associated with endurance training - during recovery in the whey protein isolate group compared with the carbohydrate group. Another indicator or mitochondrial biogenesis (AMPK-α2 mRNA expression) was decreased in the carbohydrate group but not the whey protein isolate group at the 6hour recovery point.

The researchers conclusions about whey protein and endurance training recovery

The researchers concluded that co-ingestion of carbohydrate and whey protein isolate appears to be important for endurance training adaptations, through increasing plasma insulin and may enhance mitochondrial biogenesis.

Whey protein for endurance recovery summary:

Consuming additional protein (whey protein isolate), along with adequate carbohydrate, as part of your daily diet and as a post exercise recovery drink appears to be beneficial for increased rates of recovery.

Considerations

The amount of additional whey protein used in this study was fairly high with an additional 1.2g kg/bw of whey protein isolate consumed in the high protein dietary intervention phase – equivalent to 84g for a 70kg athlete which equates to just over three normal size servings of whey protein isolate. It’s not clear whether similar results would have been achieved if a smaller amount of whey protein was consumed daily (e.g. 25-50g whey protein isolate).

The high protein post exercise drink also contained a fairly significant amount of protein (1.1g kg/bw – equivalent to around 77g of whey protein isolate for a 70kg athlete). Whilst the higher post exercise protein consumption was more beneficial, it’s not clear whether a slightly lower protein intake may prove equally effective and more cost effective. There was quite a large difference in the amount of protein used in the two groups (1.1g vs 0.4g kg/bw – equivalent to 77g vs 28g in a 70kg athlete) and it may be that somewhere between the two (e.g. 50g of whey protein isolate) may prove to be equally effective and significantly more cost effective than consuming 3 or more servings. It’s also important to consider that muscle protein synthesis is maximally stimulated following consumption of around 25g of whey protein and therefore consuming more in one dose may not be beneficial. In view of this you should consider splitting the protein intake into two smaller doses e.g. consume 25g of protein immediately following endurance exercise and a separate 25g dose 2-3hours later.

A further consideration is the intensity or duration of exercise – a single 25 serving of whey protein may be equally effective following low intensity (<80% HR max) short duration exercise (<60 minutes duration). Whereas taking two 25g whey protein servings (separated by 2-3 hours) may prove to be more effective following higher intensity training (e.g. lactate threshold training or high intensity interval training) or prolonged exercise (e.g. 2+ hours duration).

]]>Review of why most dieters regain weight after weight losshttp://www.strengthandfitnessuk.com/news/weight-loss/review-of-why-most-dieters-regain-weight-after-weight-loss
A recent review article (Sumithran and Proietto 2013) looked at the reasons why the most dieters regain weight in the long term.

Physiological changes after dieting and weight regain

The researchers highlighted a number of physiological changes that occur following dieting/weight loss and lead to increased likelihood of weight regain. Many of these changes may be long term changes that persist for 1 year or more after a diet, making it difficult to maintain weight loss in the long run. Some of these changes include reduced energy expenditure, reduced rates of fat metabolism, suppression of the sympathetic nervous system, hormonal changes, and increased appetite.

Reduced energy expenditure after dieting and weight regain

Total energy expenditure is dependent on a number of factors one key factor is bodyweight which can affect metabolism. Following dieting bodyweight decreases and therefore energy expenditure will also decrease. However, the decrease in total energy expenditure, following dieting, is not proportional to the decrease in bodyweight and can be as much as 15% below that which can be attributed to the reduced bodyweight. Research suggests that the increased reduction in total energy expenditure may persist for >1 year after weight loss.

Reduced rates of fat metabolism after dieting

Following weight loss the rate of fat metabolism appears to decrease and may lead to increased rates of fat storage.

Changes to nervous system activity after dieting

Weight loss appears to impair sympathetic nervous system activity which may negatively affect energy expenditure and rates of fat metabolism.

Hormonal changes following weight loss

Weight loss appears to affect a number of circulating hormones (e.g. leptin, insulin, amylin and ghrelin) in a way that increases/promotes the rate of weight regain. Many of these changes appear to persist for a period of months following dieting.

Increased appetite after dieting

Weight loss appears to affect appetite in two main ways: 1) increased appetite, and 2) increased pleasure from eating.

Best strategies for maintaining weight loss

The researchers highlighted a number of key strategies used by dieters who have successfully managed to maintain weight loss these included: 1) Undertaking regular moderate intensity exercise equivalent to ~1hr/day; 2) Eating breakfast every day – skipping breakfast negatively affects weight loss/maintenance; 3) Sticking to a consistent low calorie (~1300 and ~1700kcal/day for women and men respectively), low fat diet (<25% of total calories coming from fat); 4) regular weight monitoring, ideally at least once weekly; 5)Limiting time in front of the telly to less than 10h/week.

Weight Loss Review Reference

]]>Endurance training may slow the ageing processhttp://www.strengthandfitnessuk.com/news/endurance-training/endurance-training-may-slow-the-ageing-process
Recent research (Østhus et al., 2012) suggests that long term endurance training may slow the ageing process by maintaining telomere length – having shorter telomeres is associated with ageing and is an indicator of life expectancy.

What is a telomere and why is telomere length important?

A telomere is a region made of repetitive DNA situated at the end of each chromosome. They protect the cells chromosomes from fusing with other chromosomes and from deterioration. Every time a cell divides the telomeres get a little bit shorter and at a certain point they become too short and the cell becomes inactive or dies. The process by which telomeres get shorter has been associated with aging, cancer and an increased risk of death. Some studies have found an association between shorter telomeres and reduced life expectancy, especially amongst older people. Therefore, anything that helps to maintain telomere length may be of benefit in delaying the aging process.

About the endurance training research

The researchers looked at the telomere length in groups of young (22-27 years) and older (66-77 years) men – in both groups half of the participants were endurance athletes and half were moderately active. Mean telomere length was measured as the telomere/single copy gene-ratio (T/S-ratio).

The effects of endurance training on ageing

In both the young and older athletes telomere length was longer in athletes than the moderately active groups (1.47 vs 1.33 – Young, 1.12 vs 0.92 - Older). The difference was significantly greater amongst the older group indicating that endurance training may help to better maintain telomere length than moderate activity levels as we age.

Figure 1. shows the telomere length (T/S ratio) in a group of athletes and non-athletes.*P<0.05. doi:10.1371/journal.pone.0052769.g001

The researchers also found a positive relationship between VO2max and mean telomere length. This relationship was stronger when comparing endurance trained athletes than the moderately training participants.

The researchers conclusions on endurance training and ageing

The researchers stated that telomere length appeared to be better preserved in older endurance trained athletes than similarly aged moderately active individuals. The researchers concluded that: 1) Endurance training appears to helps to regulate the telomeres in old age and may slow the ageing process by maintaining telomere length; 2) The positive relationship between VO2max and telomere length highlights the importance of aerobic fitness for healthy ageing.

Recent research has provided further evidence for the support of slow movement repetitions for muscle building. In this study older men and women performed low intensity (50% of 1 rep max) resistance exercises (leg extensions and flexion) to working the quadriceps and hamstring muscle groups. One group completed the repetitions at a normal speed (1-second concentric phase [lifting phase], 1-second eccentric phase [lowering phase] and 1-second rest between each repetition) whilst the experimental group completed the repetitions at a much slower speed (3-second concentric phase, 3-second eccentric phase, and 1-second isometric with no rest between the repetitions).

The effect of slow movement resistance training on muscle size and strength

The researchers found that whilst both groups increased strength it was only the slow repetition group that showed significant increases in thigh muscle thickness. Therefore, for older individuals the combination of low intensity resistance exercise (i.e. 50% of 1RM) with slow movement speed (3-second concentric and eccentric with 1-second isometrics) appears to effective for muscle building.

]]>Maintain the same relative intensity for continued training adaptationshttp://www.strengthandfitnessuk.com/news/endurance-training/maintain-the-same-relative-intensity-for-continued-training-adaptations

Recent research looked at the effect of 10 days of intensified training (HIIT and moderate intensity training) on mitochondrial gene expression and subsequent training adaptations, following training at the same absolute exercise intensity.

The high intensity interval training sessions

The researchers looked at mitochondrial gene expression following four high intensity interval training sessions (6 x 5 minutes at 90-100% VO2max) and six moderate intensity training sessions (45-90minutes at 75% VO2max) over a 10-day training period. Prior to the exercise training subjects performed a 60minute cycle at 164±18 W (72% of pre-training VO2max). The 60minute exercise trial was repeated after the 10-day training period and performed at the same absolute intensity which corresponded with 64% of pre-training VO2max.

What the researchers found

The main finding of the research was that following the training period there was reduced mitochondrial gene expression (PGC-1α mRNA expression) at the same absolute exercise intensity the work intensity was maintained in the second exercise bout however the relative intensity was lower (72% vs. 64% VO2peak pre- and post-training respectively) and indicates the importance of maintaining the same relative intensity for continued training adaptations. Additional findings were that short term intensified training (4 HIIT sessions over a 10-day period) led to increased mitochondrial gene expression and protein abundance.

Practical Implications – as your fitness/performance level increases you should ensure you train at the same relative exercise intensity (e.g. same percentage of maximum heart rate) for continued training adaptations. The best way to do this is to work at a percentage of your maximum heart rate which will help to ensure that as your fitness improves so does your absolute work intensity.

Recommended protein and calorie intake for muscle building

Leucine and muscle building

Leucine is one of the branched chain amino acids (BCAAs) and has been shown to have a significant effect on rates of muscle hypertrophy. In fact it is believed that Leucine may be the sole stimulator of muscle protein synthesis and appears to be nearly as effective for stimulating rates of muscle protein synthesis as the consumption of all of the BCAAs. Accordingly it is important that foods or protein drinks contain adequate amounts of leucine to stimulate muscle protein synthesis. It is currently recommended that ~3-4g of leucine are consumed per serving.

Best types of protein for muscle building

Each protein source can be scored on its bioavailability (BV) and protein digestibility corrected amino acid score (PDCAAS).

1) Milk Protein – a highly bioavailable protein source consisting of 80% casein & 20% whey that provides all of the essential amino acids (EAAs). It has good bioavailability with a BV of 91 and a PDCAAS of 1.00. The researchers state that milk protein is a readily absorbed protein source, that promotes muscle protein synthesis and tissue repair.

2) Casein Protein – the main protein found in milk it contains all the essential amino acids (EAAs). It is less bioavailable than milk protein with a BV of 77 and a PDCAAS of 1.00. Casein protein provides a more sustained release of amino acids due to the way it clots within the stomach.

3) Whey Protein – like milk and casein protein it contains all the essential amino acids but has greater bioavailability with a BV of 104 and a PDCAAS of 1.00. The researchers state that whey protein has excellent bioavailability that leads to rapid increases in rates of protein synthesis.

4) Soy Protein – contains all the EAAs but has a lower bioavailability than milk, casein or whey protein with a BV of 74 and PDCAAS of 1.00.

The researchers conclusions on protein intake for muscle building and strength

Consuming protein supplements either before or after a workout leads to improved recovery, lean body mass, physical performance, muscle hypertrophy and strength.

Whey protein is more effective than casein protein in the development of muscle strength.

Milk protein is superior to soy proteins for both lean body mass and muscle hypertrophy.

Consuming protein increases the rate of anabolism (muscle building) for approximately 3hours with peak rates of anabolism occurring ~45-90minutes post consumption. There is therefore only a limited time period post exercise in which to consume protein and maximize the rate of anabolism. In view of this whey protein is considered a good protein source due to its high bioavailability and rapid digestibility.

When consumed after exercise whey protein is more effective when combined with a fast acting carbohydrate like maltodextrin or glucose.

The consumption of essential amino acids (EAAs) appears to be more effective at increasing protein synthesis before exercise, particularly when combined with dextrose.

Reference

Stark M, Lukaszuk J, Prawitz A, and Salacinski A (2012) Protein timing and its effects on muscular hypertrophy and strength in individuals engaged in weight-training. Journal of the International Society of Sports Nutrition 2012, 9:54

]]>Lycopene in tomato juice protects against exercise induced oxidative stresshttp://www.strengthandfitnessuk.com/news/nutrition/lycopene-in-tomato-juice-protects-against-exercise-induced-oxidative-stress
Recent research has found that the consumption of just 150ml of tomato juice daily (equal to 15mg lycopene) protected against exercise induced increases in 8-oxodG, indicating reduced levels of oxidative stress and DNA oxidation.

About the tomato juice/lycopene research

The researchers recruited 15 healthy but untrained subjects and asked them to consume 150ml of tomato juice (containing 0.1mg lycopene per ml) daily over 2 periods of 5 weeks, this was separated by 5 weeks without tomato juice. The researchers took blood samples before and at the end of each 5 week period. Immediately following the collection of blood samples the subjects underwent 20 minutes of cycling exercise at 80% of maximum heart rate. The researchers then took a second blood 1 hour after the completion of the cycling exercise. The blood samples were used to analyse levels of 8-oxodG (a marker of oxidative stress) before and after exercise.

What the researchers found

The researchers found that without tomato juice the level of 8-oxodG increased following exercise, by an average of 42% and 84% (at start of trial and after the 5 week wash out period respectively) indicating increased levels of oxidative stress and DNA oxidation. However, the consumption of tomato juice protected against this rise in 8-oxodG with average changes in 8-oxodG levels of -22% and 26% following exercise in the first and second 5 week tomato juice consumption period respectively.

The researchers stated that the daily consumption of 150ml of tomato juice (containing 15mg lycopene) provided significant protection against reactive oxygen species produced during intense exercise. The researchers point out that along with lycopene tomato juice also contains vitamin C, tocopherols and polyphenols, however, they attribute most of the antioxidant activity of tomato juice to the lycopene content.

Interestingly the tomato juice did not appear to influence the level of oxidative stress when this group of healthy subjects were at rest but provided protection when there was increased production of reactive oxygen species (free radicals) – in this case following a period of acute exercise. In this way the lycopene in tomato juice may provide protection for people with conditions that increase levels of oxidative stress. The researchers suggest that tomato juice may reduce oxidative stress levels in patients with increased levels of oxidative stress such as those with diabetes, cardiovascular disease, or inflammatory diseases and conclude that “data strongly suggest that tomato juice has a potential antioxidant effect and may reduce the elevated level of ROS induced by oxidative stress.”

Summary of the effects of tomato juice/lycopene research

Exercise increased oxidative stress in healthy but untrained subjects

150ml of tomato juice (equal to 15mg of lycopene) protected against the exercise induced reactive oxygen species and oxidative stress

The lycopene in tomato juice may be beneficial for patients with conditions that increase oxidative stresss

Reference

]]>Vitamin D levels associated with improved physical performance in the elderlyhttp://www.strengthandfitnessuk.com/news/health-supplements/vitamin-d-levels-associated-with-improved-physical-performance-in-the-elderly
A recent large scale population based research study (2594 participants) looking at the association between serum levels of vitamin d and measures of co-ordination, strength, and fitness in the elderly, found that optimal physical performance occurred in subjects with the highest serum vitamin d levels (Toffanello et al., 2012).

About the vitamin D research

The researchers looked at the relationship between serum 25-hydroxyvitamin D (250HD) – the serum 25-hydroxyvitamin D level is used to determine how much vitamin D is in the body – and a number of performance measures including: 1) Tandem test – a measure static balance ability; 2) 5 timed chair stands (TCS) – a measure of coordination and strength; 3) Gait speed; 4) 6-minute walking test (6 mW) – a measure of aerobic capacity; and 5) Handgrip and quadriceps strength – a measure of upper and lower body strength.

About the subjects
The research sample was made up of 2594 elderly subjects (1597 Females and 1097 Males) with mean ages of 75.6 y (±7.5) in women, and 76.2 y (±7.8) in men. Vitamin D deficiency was observed in 40% of women and 20% of men with severe deficiency present in 13.5% of women and 5.9% of men.

The results of the vitamin D research

The researchers found significant relationships between the levels of vitamin d and the: Timed chair stands test, Gait speed test, 6-minute walk test, and the Handgrip strength test. There was no significant relationship between the tandem test performance and quadriceps strength test in either men or women.

The researchers concluded that lower 25OHD levels – an indication of vitamin d levels within the body - are associated with a reduced coordination and strength in women, a slower walking time and reduced handgrip strength in men, and a reduced aerobic capacity in both genders. They suggest that “For optimal physical performances, 25OHD concentrations of 100 nmol/L appear to be more advantageous in elderly men and women, and Vitamin D supplementation should be encouraged to maintain their 25OHD levels as high as this threshold.”

In addition the researchers found that, after adjusting for age, both the male and female subjects with the lowest levels of vitamin D were significantly less active, had greater levels of depression and were more cognitively impaired than participants with the highest levels of vitamin D.

]]>Caffeine improves morning exercise performancehttp://www.strengthandfitnessuk.com/news/sports-nutrition/caffeine-improves-morning-exercise-performance
Any strength or endurance athlete who has trained in the early morning or late at night will be well aware that their exercise performance is often reduced compared with afternoon and evening training. This process by which sporting performance is affected by the time of day is governed by our circadian rhythm - often referred to as our body clock - and has been shown to measurably reduce morning exercise performance in both strength/power events and endurance events. The exact reasons for the decline in exercise performance are not completely clear, however, it is generally believed that variations in hormones, body temperature, heart rate and blood pressure appear to play a role. Recent research has found that the consumption of caffeine (3mg/kg bodyweight) reversed the morning reductions in maximum dynamic strength and muscle power output, increasing muscle performance in highly-resistance trained men to the levels found when training in the afternoon (Mora-Rodriguez et al., 2012).

About the Caffeine Research

The researchers recruited twelve highly resistance-trained men (age 19.7±2.8 yr, body mass 74.6±2.3 kg, body fat 11.6±0.8%, resistance training experience 7.2±2.4 yr) to take part in the experiment - a randomized, double-blind, crossover, placebo controlled experimental design with all subjects serving as their own controls. Each subject underwent three testing conditions: 1) Morning testing with caffeine (10:00AM); 2) Morning testing with placebo (10:00AM); 3) Afternoon testing with placebo (18:00). The caffeine and placebo capsules were ingested 60 minutes before testing. Subjects refrained from physical activity as well as alcohol, tobacco and caffeine for 4 days before testing.

During the experiment the researchers measured a number of measures of strength and power including: 1) Velocity for maximum power load; Velocity for maximum strength loads (i.e., load of 75% 1RM); 2) Maximal isometric voluntary contraction on the right knee(MVCLEG); 3) Maximal isometric contraction of the right hand (MVCARM); 4) Electrically evoked maximal isometric contraction (EVOKLEG) of the right knee extensors; 5) subjects also completed 1 set of 6 free-weight full squat repetitions at 85% of 1 RM and blood samples were taken to measure the plasma epinephrine (E) and norepinephrine (NE) concentration – this was used as an index of whole body sympathetic nerve activation. Blood hematocrit and hormone levels (i.e., serum testosterone, cortisol, growth hormone, and plasma nor-and-epinephrine) were evaluated at the beginning of each trial (PRE) and catecholamines at the end of the maximal sympathetic stimulation bout of exercise (POST).

What effect did caffeine have on morning exercise performance?

Caffeine ingestion increased the squat and bench press muscle power output by 2.5-5.7% compared with the AM placebo. There was no significant difference between AM caffeine or PM placebo indicating that caffeine restored morning muscle power output to afternoon levels.

The velocity for maximum strength loads (load of 75% 1RM) was significantly greater in the AM caffeine than in the AM placebo group, for both the squat and bench press (5.3% and 4.6% improvement respectively). There was no significant difference between the AM caffeine or PM placebo group indicating that caffeine restored muscle strength to afternoon levels.

The electrically evoked right leg muscle strength test was significantly higher in the AM caffeine compared with the AM placebo (16%)

The concentration of plasma norepinephrine increased 5x after the AM Caffeine trial and was significant higher than in the AM placebo trial

Caffeine had a significant effect on dynamic muscular contractions but not on isometric contractions

What does the research tell us about the use of caffeine during morning workouts?

The researchers suggest that not only does their research support the use of caffeine as an ergogenic aid but also suggests that caffeine ingestion prior to a morning workout actually restores neuromuscular performance (strength and power output) to the levels produced in an afternoon training session. They found that caffeine ingestion increased squat and bench press power output by 2.5-5.7% and improved the velocity for maximum strength loads by 5.3% and 4.6% in the squat and bench press. The researchers observed that neuromuscular performance - maximum dynamic strength and muscle power output - improved in the range of 3–6% and stated that the observed strength and power enhancements following caffeine (3mg/kg-1 – equivalent to 2.5 espresso coffees for a 75 kg athlete) “have the potential to prevent the morning declines in sport performance, allowing athletes to train and compete at the level of the evening”

The researchers concluded that caffeine reverses the morning reductions in maximum dynamic strength and muscle power output (2.5-7.0%), increased muscle performance to the levels found in an afternoon training session and “avoids the morning reduction in muscle performance due to circadian rhythm”.

In summary:

3mg/kg-1 – equivalent to 2.5 espresso coffees in a 75kg athlete – improved dynamic muscle strength and power output compared with a placebo

Caffeine increased performance levels to those seen in an afternoon session reversing the normal circadian rhythm

]]>Red wine compound piceatannol inhibits the development of fat cellshttp://www.strengthandfitnessuk.com/news/weight-loss-supplements/red-wine-compound-piceatannol-inhibits-the-development-of-fat-cells
Piceatannol (3,4,3′,5′-tetrahydroxy-trans-stilbene), a metabolite of resveratrol found in red wine, grapes, rhubarb, passion fruit seeds, blueberries, and peanuts appears to inhibit adipogenesis – the process by which preadipocytes (immature fat cells) develop into adipocytes (mature fat cells) – in part through the inhibition of insulin receptor activity in preadipocytes (Kwon et al., 2012). The research suggests that piceatannol may therefore be beneficial for the treatment/prevention of obesity.

Why is the inhibition of adipogenesis important?

Any inhibition of adipogenesis is important since when adipocyte numbers increase significantly – as is the case with obesity - there is often a concomitant increase in the release of pro-inflammatory molecules, fatty acids and hormones which may lead to a permanent pro-inflammatory state. It is believed that the inflammation associated with obesity may play a significant role in a number of health conditions including, metabolic syndrome, type 2 diabetes, atherosclerosis, and nonalcoholic fatty liver disease.

]]>Betaine improves sprint cycling performancehttp://www.strengthandfitnessuk.com/news/sports-nutrition/betaine-improves-sprint-cycling-performance
Research reported in the Journal of the International Society of Sports Nutrition found that supplementation with Betaine (Trimethylglycine), at a dose of 2.5g/daily for 7-days significantly improved cycling sprint performance (Pryor et al., 2012).

What is Betaine (trimethylglycine)?

Betaine (or Trimethylglycine) is an important nutrient found in a variety of foods (whole grains, spinach, sea food etc). It is an organic osmolyte that is known to possess osmoprotective properties - it protects cells during periods of physical stress stress, such as dehydration or heat stress. Betaine is also known to be a methyl donor – the process of transferring a methyl group (CH3) is called methylation and is known to be important for a number of biochemical processes including the synthesis of neurotransmitters, metabolism of lipids, DNA, and cellular reproduction. Betaine appears to be beneficial for liver, heart, and kidney health as well as for lowering homocysteine levels.

The betaine research

The researchers compared the effects of a carbohydrate electrolyte drink containing 2.5g of betaine with a placebo (the same drink without betaine). Subjects (sixteen college age males and females) completed an initial sprint cycling test for baseline test figures and were then assigned to either placebo or betaine groups – subjects were unaware of which group they were assigned to – and instructed to consume half of their drink twice daily for a seven day period followed by a second cycling sprint test. All subjects then had a three week washout period before consuming the opposite drink for seven days and completing a third cycling sprint test. The sprint tests consisted of four 12 second maximum work bouts (resistance was set to 5.5% of body weight during sprints) separated by 2 ½ minutes cycling with no resistance.

The results

Supplementation with betaine was found to significantly increase sprint cylcling performance compared with baseline figures (5.5 ± 0.8% increase compared with baseline) and compared with the placebo drink (3.5 ± 0.2% increase compared with placebo). The researchers suggest that the increase in cycling sprint performance may be due to betaine supplementation increasing stores of muscle creatine, enhancing muscle growth, or through the protection of muscle cells from stress-induced damage.

]]>Green coffee bean extract shows potential for weight losshttp://www.strengthandfitnessuk.com/news/weight-loss-supplements/green-coffee-bean-extract-shows-potential-for-weight-loss
Recent research presented at a meeting of the American Chemical Society (ACS) - the worlds largest scientific society - has reported new evidence supporting green coffee bean extract as a potential weight loss supplement. The research was part of a pilot study, led by Professor Joe Vinson, PhD, with a larger study of about 60 people planned. Two doses of green coffee bean extract were used in the study (700mg and 1,050mg) as well as a placebo over a 22 week period. The researchers found that the greatest reductions in bodyweight occured with the highest dose, with an average weight loss of just over 10%.

Why does green coffee bean extract appear to be beneficial for weight loss?

It's known that coffee made from roasted coffee beans have a protective effect against type II diabetes and may be beneficial for weight loss. However, the roasting process is known to reduce both the antioxidant activity and the amount of an important polyphenol, chlorogenic acid, present in the coffee beans. Chlorogenic acid appears to be able lower blood glucose levels and helps to lower bodyweight.

]]>Green tea extract egcg has pronounced antidiabetic effecthttp://www.strengthandfitnessuk.com/news/health-supplements/green-tea-extract-egcg-has-pronounced-antidiabetic-effect
Researchers have found that green tea extract (EGCG) enhanced glucose tolerance in genetically diabetic mice (Ortsater et al., 2012). The researchers compared the effects of dietary supplementation of EGCG (10 g/kg of diet) or rosiglitazone (21 mg/kg of diet) - an antidiabtetic drug that works as an insulin sensitizer that makes cells more responsive to insulin - in 7-week old pre-diabetic mice. Fasting blood glucose levels, body weight and food intake was measured during the treatment.

After 10 weeks the mice treated with either green tea extract had significantly lower fasting blood glucose levels compared with the control group (9.3mM±1.1 vs 14.7mM±1.8). The researchers found that green tea extract appeared to attenuate the death of beta cells - Beta cells store insulin and respond to spikes in blood glucose levels by releasing insulin which controls the level of glucose in the blood. It was suggested that green tea extract appears to exert its antidiabetic activity through a combination of reducing insulin resistance and increasing the glucose-induced insulin secretion via the preservation of functional beta cell mass. The green tea extract was also associated with increases in insulin content and with the preservation of pancreatic islet structure – Islets contain the hormone producing beta cells.

The researchers concluded: “this study demonstrates that a pharmacological dose of the green tea catechin, EGCG, possesses pronounced antidiabetic efficacy in vivo – comparable to the effect seen with rosiglitazone” and that the “total plasma EGCG levels shown to be efficacious in mice and rats can be reached by dietary supplementation of EGCG.” However, it should be noted that the amount of green tea extract used in this study was fairly high, making up 1% of the mice diet.

]]>Protein Intake Linked To Reduced Central Abdominal Fathttp://www.strengthandfitnessuk.com/news/weight-loss-supplements/protein-intake-linked-to-reduced-central-abdominal-fat
Recent research (Loenneke et al., 2012) provides evidence of the benefit of quality protein intake in reducing central abdominal fat (CAF). In this study researchers looked at the amount of quality protein that was consumed in a 24 hour period and the amount of times that the essential amino acid (EAA) threshold was reached in a day – the EAA threshold was defined as when ~10g of EAA was consumed at a meal. EAAs play an essential role in stimulating muscle synthesis and previous research has demonstrated that approximately 10g of EAAs is sufficient to maximally stimulate muscle protein synthesis – greater intakes of EAAs do not appear to provide additional benefit as muscle protein synthesis appears to plateau above 9-10g of EAAs.

The research looked at EAA consumption amongst 27 healthy males (n=12) and females (n=15) (Age = 22 ± 3 yrs.; Weight = 71.7 ± 13.9 kg). EAA consumption was determined from a 3 day food record, averaged across the 3 days, and the amino acid profile was determined using a computer programme. The CAF level was determined using a total body DXA scan.

The researchers found that both the quality of the protein consumed and the distribution of the protein consumption throughout the day, was an important factor in determining the level of central abdominal fat. The researchers also found a significant relationship between how many times the EAA threshold was reached per day and the percentage of CAF, with subjects who reached the EAA threshold more times having a tendency to have lower levels of CAF. The researchers did not find significant association between carbohydrate or fat consumption and CAF levels amongst this group of healthy subjects. They concluded that the results of their study “indicate that quality and distribution of protein may play an important role in regulating CAF, which is a strong independent marker for disease and mortality.”

Why are EAAs believed help to regulate body fat levels?

EAAs are known to increase the levels of muscle protein synthesis which can increase the quantity of lean muscle mass. Since, muscle mass is a significant contributor to the resting metabolic rate any increase in lean mass will also lead to increases in the resting metabolic rate. The results of this study will not come as a particular surprise to many in the fitness industry who have routinely taken protein supplements, particularly whey protein supplements, for both increasing lean mass and as an aid to reducing body fat levels.

How much EAAs are in whey protein?

The quantity varies depending on the protein concentration of the whey protein powder but typically you would need between 25g (whey protein consisting of 90% protein) and 30g (whey protein consisting of 70% protein) to achieve the EAA.

How many times a day should you take the whey protein to maximise results?

The results of this study suggest that the greatest benefits occur when you consume 10g of EAAs on two or more occasions daily. Therefore, you may benefit from consuming 30g of whey protein on 2-3 separate occasions daily. You should try to separate each serving by around 2-3 hours and try to take away from meals.

Reference

]]>Grape Seed Extract Proanthocyanidins Inhibit The Invasiveness of Head and Neck Cutaneous Squamous Cell Carcinoma Cellshttp://www.strengthandfitnessuk.com/news/health-supplements/grape-seed-extract-proanthocyanidins-inhibit-the-invasiveness-of-head-and-neck-cutaneous-squamous-cell-carcinoma-cells
Recent research (Sun et al., 2011) indicates that grape seed proanthocyanidins - a significant component of grape seed extract - have the ability to inhibit the invasion of Head and neck squamous cell carcinoma (HNSCC). HNSCC is the sixth most common cancer worldwide and has higher death rates than cancers of the colon, breast or melanoma. It affects approximately 40,000 people in the United States and 8,000 people in the UK annually. Most of the deaths are due to HNSCC’s propensity to metastasize (spread from one organ or part of the body to another). The treatment of head and neck squamous cell carcinoma is complex partly due to the constraints of treating the head and neck as well as protecting organ function.

The researchers examined the effect of bioactive component grape seed proanthocyanidins on HNSCC cell invasion and looked at the molecular mechanisms underlying these effects. They found that treatment with grape seed proanthocyanidins inhibited cell invasion by the cancer cells in a dose dependent manner. The inhibition of the cancer cells by grape seed proanthocyanidins was associated with a reduction in levels of epidermal growth factor receptor. The epidermal growth factor receptor (EGFR) signaling pathway helps to regulate cell growth, survival and proliferation. It is known that epidermal growth factor receptor (EGFR) is overexpressed in many types of cancers and therefore any reduction in levels of epidermal growth factor receptor levels may be beneficial to cancer patients.

The inhibition of cell invasion by grape seed proanthocyanidins was associated with the inhibition of the phosphorylation of extracellular-signal-regulated kinases (p-ERK) and was associated with the reversal of the epithelial-to-mesenchymal transition (EMT) process. Previous research suggests that p-ERK plays a critical role in the cell proliferation of malignant disease whilst EMT has been associated with the increased aggressiveness, invasive and metastatic potential of cancer cells.

The researchers concluded that grape seed proanthocyanidins have the ability to inhibit the invasion of human Head and neck squamous cell carcinoma by targeting epidermal growth factor receptor expression and reversing the epithelial-to-mesenchymal transition process. The researchers stated: “These data suggest that GSPs can be developed as a complementary and alternative medicine for the prevention of invasion/metastasis of HNSCC cells.”

A recent study published in the Journal of the International Society of Sports Nutrition (Peltier et al., 2011) found that the consumption of a sports drink containing a combination of carbohydrates, branched chain amino acids (BCAAs) and Caffeine significantly increased running performance during a 2-hour treadmill run. The sports drink also helped to maintain glycemia (blood glucose) whilst significantly decreasing the rate of perceived exertion (RPE) and central fatigue compared with the placebo drink.

Why did the researchers look at the combined effects of Carbohydrates, Caffeine and BCAAs?

Previous studies have demonstrated that carbohydrate and caffeine ingestion can improve/prolong endurance exercise performance, and it has also been suggested that BCAA consumption may also have positive effects on endurance exercise performance. Both carbohydrate and caffeine consumption before and during exercise can help to preserve muscle glycogen levels, caffeine consumption can also increase fat metabolism and decrease central fatigue and the rate of perceived exertion (RPE), whilst BCAA consumption can decrease the rate of muscle breakdown, may preserve muscle glycogen, and has been postulated to reduce central fatigue. However, no previous studies have looked at the combined effects of carbohydrates, caffeine, and BCCAs on endurance exercise performance.

What Did The Researchers Find?

The researchers found that the consumption of 2litres of sports drink (Energy = 1254kJ/l, Carbohydrate = 68.6 g/l, BCAAs = 4 g/l, and caffeine = 75 mg/L) before (250ml 15 minutes before exercise) and during exercise (250ml every 15 minutes of exercise) significantly improved performance (by 1.9%) compared with the consumption of 2litres of placebo drink (Energy = 50KJ/l). Whilst the 1.9% doesn’t sound like a significant difference it equated to an average difference of 410 meters over the 2 hours. Based on the distance covered by the two groups, 22.31 ± 1.85 km for the sports drink group vs. 21.90 ± 1.69 km for the placebo drink group, we can calculate that the placebo group were approximately 2 mins and 15 seconds behind the sports drink group. The researchers hypothesized that the improvement seen in the sports drink group may have been limited because the subjects were not fasted (overnight) and therefore initial muscle glycogen levels were high. However, by not fasting overnight the improvement is likely to more accurately reflect the beneficial effects of the sports drink over the placebo since most athletes will carbo-load prior to a prolonged endurance event to ensure muscle glycogen levels are maximized.

The researchers also found that the sports drink reduced central fatigue and RPE. However, it wasn’t possible for the researchers to establish the individual contribution of each of the main ingredients on central fatigue or RPE. Since it is already known that both carbohydrate and caffeine consumption can improve endurance it is not clear whether the addition of BCAA to sports drink further enhanced performance or reduced central fatigue beyond that of carbohydrate and caffeine consumption alone.

In Summary:

The consumption of sports drink containing carbohydrate, BCAAs and caffeine before and during exercise is beneficial to performance during prolonged endurance exercise. It wasn’t clear what the contribution of each was to the improved exercise performance. It is already established that both carbohydrate and caffeine can enhance endurance exercise performance but the effect of BCAAs is less clear. However, since BCAAs will not negatively impact performance and have been shown to reduce post exercise muscle breakdown it seems logical to include them in any sports drink either during training or competition.

Creatine Monohydrates Antioxidant Capacity

A recent research study provides further evidence to support creatine monohydrates antioxidant properties (Rahimi 2011). Previous studies have highlighted the antioxidant potential of creatine (Lawler et al., 2002; Royes et al., 2006; Sestili et al., 2011). In this study (Rahimi 2011) the researcher looked at whether creatine monohydrate could reduced oxidative stress by looking at two known markers of oxidative stress: 1) Malondialdehyde (MDA) - a highly reactive naturally occurring organic compound that is a marker for oxidative stress and indicates lipid peroxidation, and 2) 8-hydroxy-2-deoxyguanosine (8-OHdG) - a widely used biomarker for oxidative stress and carcinogenesis. It appears that creatines antioxidant properties may provide some protection against damage to DNA and lipids.

In Summary:

In addition to the research proven benefits of creatine monohydrate on sporting performance it also appears to provide protection against the oxidative stress and oxidative damage induced by resistance exercise.

]]>More Evidence to support the role of caffeine in enhancing endurance exercise performancehttp://www.strengthandfitnessuk.com/news/sports-nutrition/more-evidence-to-support-the-role-of-caffeine-in-enhancing-endurance-exercise-performance

Caffeine Consumption Improves 5,000m Time Trial Performance

A recent study found that the consumption of caffeine, in the form of caffeine anhydrous, improved 5,000m time trial performance by an average of 51 seconds (Marangon and Mendes 2011). The subjects, 9 male triathletes aged between 18 and 35, completed two 5,000m time trials which were separated by an average of 7 days. Prior to one of the time trials the subjects took a capsule containing caffeine anhydrous (5mg/kg - this equates to 350mg for a 70kg athlete) and for the other time trial they took a placebo capsule.

Caffeine supplementation had no significant effect on either Blood lactate or glucose levels before or after either treatment. However, the mean time to complete the time trial was significantly quicker for the caffeine group (20.48±3.15 min) than the placebo group (21.39±3.1 min) with a mean improvement in time of 51±3.2 seconds.

Caffeine and Endurance Exercise Performance

Caffeine is known to enhance exercise performance through a number of different pathways including activation of the central and sympathetic nervous system, the cardiovascular system as well as neuro-muscular activation. The combined effects of these lead to increased muscle recruitment, enhanced aerobic and anaerobic metabolism, and a delay in fatigue levels by a reduction in the athlete’s perception of fatigue/effort.

The researchers concluded that caffeine is a powerful ergogenic that shows beneficial effects on aerobic performance.

Reference:

Mendes P HM (2011) Caffeine influence on the performance of the 5000m race. Journal of the International Society of Sports Nutrition 2011, 8(Suppl 1):P12

High Fibre Consumption Lowers Colon Cancer Risk

Researchers from the Imperial College London have found that the risk of colon/bowel cancer can be reduced by 10% for every 10g/day of dietary fibre and cereal fibre consumed (Aune et al., 2011b). The researchers also found that there was a 20% reduction in risk when three servings (approximately 90g/day) of whole grain was consumed daily. Interestingly, they observed further reductions in risk with higher intakes of whole grain and dietary fibre suggesting that bowel cancer rates appeared to decreased linearly with increased consumption. The research was carried out by performing a meta analysis of 25 previous research studies that involved a total of 1.9 million people.

The results are particularly important since Colon cancer accounts for 9.7% of all cancer cases worldwide and is the third most common type of cancer. It is believed that a number of dietary and lifestyle play a role in increasing the risk of bowel cancer including: consumption of red meats and processed meats, excessive alcohol consumption, leading a sedentary lifestyle and/or sitting down for prolonged periods per day.

The analysis suggests that the greatest benefit came when the consumption of cereal fibre and whole grain was increased. In addition to the reduced risk of colon/bowel cancer an increase in the consumption of dietary fibre and whole grains is believed to have a number of other health benefits including: a reduce the risk of cardiovascular disease, reduced risk of type 2 diabetes, benefits for weight management/weight loss, and possibly a general reduction in overall mortality. Good sources of whole grains include: whole grain breads, whole grain wraps, cereals, brown pasta, brown rice, porridge, and oatmeal.

The researchers were unable to find any association between the intake of fibre from fruit, vegetables, or legumes and a reduction in risk of colon cancer. However, the authors pointed out that in a previous study they had found a reduction in risk with high intakes of fruit and vegetables (Aune et al., 2011a). The authors commented that the previous results suggested that there was a “potential role of components other than fibre in fruits and vegetables in explaining this result”. In fact, most current research has found that the main beneficial components that contribute to improved health and reduced cancer risk, from fruit and vegetables are the antioxidant molecules – most fruits and vegetables contain relatively high levels of antioxidants which act to protect cells from the damaging effects of free radicals.

]]>Whey Protein Helps To Delay The Age Related Decline in Muscle Masshttp://www.strengthandfitnessuk.com/news/health-supplements/whey-protein-helps-to-delay-the-age-related-decline-in-muscle-mass

Whey Protein Delays the Age Related Decline in Muscle Mass

It is well known that aging is associated with a gradual decline in muscle size and mass. This gradual loss of muscle size/mass, known as sarcopenia, is accompanied with a gradual loss in muscular strength. It is this loss in muscle strength that often makes everyday tasks more difficult for the elderly and can eventually lead to increased mobility problems and may eventually lead to disabilities.

In order to prevent or slow this gradual loss of muscle mass and strength, exercise and dietary interventions are often employed. A recent review of current dietary and exercise interventions has highlighted that the elderly may have a blunted response to lower doses of protein and appear to benefit from dietary plans including at least 20g of high quality protein per meal, and may even require as much as 30g of high quality protein per meal (Breen & Philips, 2011). The researchers suggested that high quality protein, in particular whey protein, is likely to be of particularly importance when attempting to maintain muscle mass in the elderly. The researchers highlighted that the high quality protein should provide sufficient essential amino acids (~10g), and in particular leucine (~2g).

The researchers also advise the use of resistance exercise programs for the elderly in order increase their muscle mass. This should be carefully monitored to ensure they are working within safe limits. The researchers stated that: “In older adults who are not restricted by physical disability, frequent high intensity weight lifting will increase lean muscle mass. Alternatively, low-intensity high volume weight lifting may also promote an adaptive response in the elderly”. The high intensity weight lifting would typically involve 2-3 repeated sets of around 12 repetitions per muscle group – the weight should be sufficient that they struggle to complete the final set of 12. A low intensity high volume approach would typically involve 2-3 repeated sets of around 20-25 repetitions per muscle group – again the weight should be sufficient that they struggle to complete the final set.

The researchers found the optimal response to resistance training in the elderly appears to occur when resistance training is combined with protein ingestion. When protein is consumed post exercise (ideally within 2 hours of exercise completion) it appears that the elderly may require more protein (~40g) than younger individuals (~20g). It is not clear at this point whether it is the extra quantity of protein or the higher levels of EAA’s and Leucine that are the reason why the elderly appear to benefit from the increased protein intake.

Summary of The Benefits of Whey Protein For Seniors:

Increased consumption of high quality protein appears to help to delay the age-related decline in muscle mass

The elderly should consume around 20-30g of high quality protein per meal

Whey protein appears to be the best source of protein for the elderly, it should be high in EAAs and Leucine in particular

Carefully monitored resistance training will also be of benefit to the elderly and should help to increase muscle mass

Optimal results are obtained when resistance training is combined with protein consumption

The elderly may require up to 40g of protein post exercise compared with 20g for younger individuals

It is well known that tobacco smoke contains many highly reactive oxygen species (such as hydrogen peroxide) which cause oxidative damage to any tissue that they come into contact with. The free radicals in tobacco smoke cause significant damage to vascular tissue (arteries, veins etc) and may eventually lead to damage to the blood brain barrier. It is already known that tobacco smoke can lead to significantly decreased levels of vitamin E and vitamin C in the blood plasma of smokers due to increased anti-oxidative responses to the elevated levels of reactive oxygen species.

The researchers found that pre-treatment with the antioxidant vitamins E & C can help to reduce some of the pro-inflammatory response caused by the reactive oxygen species found in tobacco smoke. The researchers suggested that “it very likely that higher concentrations and/or a sustained supplementation of vitamin C are necessary to maintain a protective effect for a longer period of time.” – possibly around 200mg/day for smokers.

It was also demonstrated that vitamin C’s protective effect was significantly enhanced, both in efficacy and duration, when combined with vitamin E. The researchers concluded that “These antioxidant vitamins may act synergistically in preventing oxidative damage and pro-inflammatory stimulation induced by tobacco smoking exposure, thereby reducing TS toxicity at the BBB level.”

Effect of Leucine-Protein Supplement on Endurance Recovery

Researchers have found that the consumption of a Leucine-Protein supplement improves recovery, as measured by the cyclists performance in subsequent bouts of interval training. The cyclists performed 2 – 2.5 hour interval training bouts on three consecutive evenings. Following each interval training session the cyclists consumed either a leucine-protein high carbohydrate supplement or an isocaloric control consisting of protein, high carbohydrate, and fat. Below is the composition of the leucine-protein high carbohydrate supplement and isocaloric control:

Leucine-Protein Drink – Leucine (0.1g/kg/hour), Protein (0.4g/kg/hour), Carbohydrate (1.2g/kg/hour), and Fat (0.2g/kg/hour). This equates to a 70 kg athlete 10.5g of leucine, 42g of protein, 126g of carbohydrate, and 21g of fat in the 90 minutes after training.

Isocaloric Control – Protein (0.06g/kg/hour), Carbohydrate (1.6g/kg/hour), and Fat (0.2g/kg/hr). This Equates to a 70kg athlete consuming 6.3g of protein, 168g of carbohydrate, and 21g of fat in the 90 minutes after training.

What did the researchers find?

Following 39 h of recovery the cyclists performed a repeat-sprint performance test to see whether the Leucine-Protein consumption had enhanced their recovery. The researchers found that the postexercise consumption of leucine-protein improved the cyclists mean sprint power by 2.5% and reduced their perceived overall tiredness during the sprints by 13%. The cyclists perceptions of leg tiredness and soreness were unaffected by the Leucine-protein consumption. The researchers also found that the Creatine-kinase (CK) concentration was lowered by 19% - the concentration of CK can indicate the level of muscle breakdown. The researchers concluded: “The ingestion of a leucine-protein supplement along with other high-carbohydrate food following intense training on consecutive days enhances subsequent high-intensity endurance performance and may attenuate muscle membrane disruption in well-trained male cyclists.”

Effect of Whey Protein on Protein Synthesis and Cardiovascular Health

A recent review of the effects of whey protein supplements on metabolism (Graf et al. 2011) highlighted the positive effects that whey protein appears to have on both glucose metabolism and muscle protein synthesis. A number of previous studies have looked at how a range of milk and dairy products are associated with reduced risk of cardiovascular disease and some metabolic disorders. The researchers stated that “In particular, whey protein seems to induce these effects because of bioactive compounds such as lactoferrin, immunoglobulins, glutamine and lactalbumin. In addition, it is an excellent source of branch chained amino acids.”

The researchers looked at 25 recently published trials that were examining the effects of whey protein supplementation on measures of cardiovascular health (lipid and glucose metabolism, blood pressure, and vascular function) and on the musculoskeletal system. The researchers found that “Whey protein appears to have a blood glucose and/or insulin lowering effect” and “protein may increase muscle protein synthesis”.

The review provides further support for the use of Whey Protein by bodybuilders as part of a balanced nutritional approach. It is particular promising to note that the as well as the apparent increased muscle protein synthesis, whey protein also has a number of beneficial effects on cardiovascular health and function.

Whey Protein Benefits Reference

]]>Vitamin B Supplement may help to delay Dementiahttp://www.strengthandfitnessuk.com/news/healthy-mind/vitamin-b-supplement-may-help-to-delay-dementia

Effect of Vitamin B Supplement on Mild Cognitive Impairment

Researchers from the University of Oxford and the University of Oslo, Norway, looking at the effect of a high dose Vitamin B supplement on Mild Cognitive Impairment (MCI) found that subjects receiving the high dose vitamin B supplements showed improvements in cognitive function compared with those taking a placebo (dummy) drug. This has important implications since 10% of all individuals with MCI develop dementia per year - approximately 50% will develop dementia within 5 years of initial MCI diagnosis – and any improvement in cognitive function could help to slow the rate of development of dementia. The research supports previous research where subjects receiving a high dose vitamin B supplemented experienced 30% less brain atrophy (shrinkage) when compared with those who only received a placebo drug.

How might B Vitamins help to reduce the rate of dementia?

It is believed that individuals who have low levels of B vitamins (either from poor diet or poor absorption of B vitamins) are at increased risk of cognitive impairment possibly due to elevated homocysteine levels in their blood – homocysteine has previously been found in higher levels in patients with Alzheimer’s. It is believed that a high dose Vitamin B supplement can help to lower homocystein levels, improve cognitive function and possibly delay the progression from MCI to dementia.

What dose of B Vitamins was used in the research?

What did the researchers find?

• The high dose Vitamin B supplement had homocysteine levels that were 30% lower (on average) compared with those receiving just a placebo drug.
• Those who received the Vitamin B supplement tended to do better in a test that looked at their ability to plan and execute a task correctly.
• The B vitamin supplement tended to be more beneficial to those individuals with higher levels of homocysteine.

Effect of High Antioxidant Consumption on Body Fat Distribution

New research indicates a link between total dietary antioxidant consumption, body fat distribution and antioxidant status in healthy young people. The researchers found an inverse relationship between the consumption of dietary antioxidants and body fat distribution – in other words the greater the consumption of antioxidants the lower the distribution of bodyfat, and the higher their antioxidant status. The researchers also found that dietary antioxidant consumption was inversely associated with glucose biomarkers – an indicator of insulin resistance.

The researchers found an association between higher dietary antioxidant consumption and lower level of specific lipid biomarkers. The researchers stated that: “an increased consumption of antioxidant-rich foods, such as fruits, vegetables, olive oil, nuts, red wine, seafood and legumes, has resulted in an improvement in the lipid profile, with increased HDL-c and decreased LDL-c and triglycerides concentrations in some intervention trial studies” – HDL is the good cholesterol and LDL is the bad cholesterol. The researchers also commented that: “polyphenols and carotenoids have the ability to reduce cholesterol absorption, to increase cholesterol and fecal bile excretion, to inhibit cholesterol synthesis and to stimulate the expression and activity of the LDL receptors”.

Summary of the research

The key findings from this research was that subjects with a higher consumption of dietary antioxidants tended to have reduced central adiposity (fat stored around the stomach) lower levels of glucose and lipid biomarkers. The link between antioxidant consuption and reduced central adiposity is particularly important since it is well known that Central adiposity carries an increased risk of type II diabetes, heart disease, hypertension and death, and is closely related to insulin resistance. Of particular importance was how this research highlighted the potential health benefits of a high intake of antioxidants even amongst a group of healthy young adults.

References

Hermana, et al. (2011) Dietary total antioxidant capacity is inversely related to central adiposity as well as to metabolic and oxidative stress markers in healthy young adults. Nutrition & Metabolism 2011, 8:59

Walnut Consumption and the Risk of Breast Cancer

New research confirms that a daily intake of just a handful of walnuts can help to significantly reduce the risk of breast cancer. The research led by Elaine Hardman, Ph.D., of Marshall's Joan C. Edwards School of Medicine looked at the effect of a diet containing walnuts and breast cancer risk in mice that were genetically programmed to develop cancer at higher rates. The researchers compared the effects of a typical diet and a diet that also contained walnuts across the lifespan of the mice: through the mother (during pregnancy and through weaning), and when eating the food directly. The amount of walnut used in the test research equates to about 2 ounces a day for humans - 2 ounces = 28 halves which supplies around 370 calories (18.5% of a 2,000 calorie diet).

They reearchers found that the group whose diet included walnut throughout their lifecycle had a 50% reduction in the rate of breast cancer development compared with the group that ate a typical diet. In addition, the mice in the walnut fed group developed tumours at a lower rate, and the number of tumours and the size of tumours were significantly smaller than the typical diet group. The researchers stated that: "These reductions are particularly important when you consider that the mice were genetically programmed to develop cancer at a high rate,".

The anticancer properties of walnuts

Antioxidants – 2oz of walnuts contain nearly double the recommended intake of antioxidants. In fact walnuts contain nearly twice the amount of antioxidants of any other commonly consumed nut. In addition the quality of the antioxidants present in walnuts is also the highest among nuts - antioxidants in walnuts have been found to be 2-15 times as potent as vitamin E.

Ellagic Acid - Ellagic acid appears to have some anti-cancer properties. It works as an anti-oxidant, and can cause cell death in cancer cells in the laboratory. It also appears to reduce the effect of estrogen in promoting the growth of breast cancer cells in tissue cultures.

Gallic acid - Gallic acid is a powerful antioxidant found in walnuts. It is believed to be beneficial to people suffering with neural disorders or who are at risk of certain cancers. Gallic acid is believed to be toxic to cancer cells, while having no negative effect on healthy cells.

Omega 3 – 2 oz of walnuts will give you nearly 200% of your daily recommended amounts of Omega 3. Omega 3 has a number of health benefits including helping to maintain a healthy heart and circulation, brain health, joint health, and may help to reduce the risk of certain cancers including breast and colon cancer.

Phytosterols - these are specific compound that resemble cholesterol and are found exclusively in plants. Phytosterols are believed to enhance our bodies own antitumor responses and directly inhibit tumor growth.

Additional considerations:

Although there are many health benefits to be gained by the addition of 2 ounces of walnuts to your diet, you should carefully adjust your daily calorific intake to accommodate the extra 300+ calories in the walnuts.